thank you so much!!! your explanation was clear and easy to understand. My professors terrible and vague explanations was making me anxious and stressed - again thanks!!!
One moment you're playing with threads the next you're learning topology of DNA with Knot theory. Every time now that I think of grandma knitting I think of knot theory.
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This is a way for me thinking of the difference and if the coilong is negative or positive. Put your thumb up like you would do when you wanna say "good job" for instance, do this with both of your hands. Picture your thumbs being the "ends" of the figures in the video, or the curves furthest away from the crossing point- your right hand shows the right end/curve, and your left hand showing the left end/curve. Then put your hands close to your desk and "rotate" your wrist forward so that your thumbs hit the desk. Your right thumb (as the right end) will rotate in the same way (forward) as positive supercoils. Your left hand (as the left end) will rotate in the same way (forward but the opposite end) as a negative supercoil. Most people ar right handed, and so am I, so I associate right with positive and left with negative.
I can't understand why in the overwound DNA the number of bp/turn decreases c.c I mean, when we use the ethidium bromide, the number of bp/turn increases and the Wr tends to become positive. Could someone explain me this? Thanks PS: The video is awesome
When you add intercalators like ethidium bromide, the binding of the intercalator to the base pairs results in a local unwinding of the helix by about 26 degrees - a reduction in twist (and an increase in writhe). Picture it - as the strands uncoil from each other slightly, the twists in the strand get further apart, so there are more bp/turn. However, this is UNtwisting the DNA from its relaxed state. In overwound DNA, intercalators are not used to wind it up. More twists are added to the double helix. As the twists in the strand increase in frequency, the number of bp/turn gets smaller.
When you have cell replication, in prokaryotes, you get two dna strand which are circular and connected with each-other thus when you want to separate the two cell dna circles from each-other you have to use the type two to losen up one of the helixes and take those two blunt ends to the other side, and from there each cell in the cell replication get a dna strand each. Otherwise you would have two interlocked dna circles. Do you understand why now?
Why can't i cross over the strand one at a time with type one instead of two at the same time with type two? It even said in the video at 4:39 that crossing over one by one yields the same result .
type two topoisomerase in bacteria helps in decreasing the linking number by two(refer Lehninger), but for eukaryotes type II topoisomerases cannot underwind DNA (introduce negative supercoils), but they can relax both positive and negative supercoils, I think what is told in the video is a bit misleading
After watching 20s to 30s of videos on thia topic... Finally!!!! I found someone who just explained this with so much ease and a dumb like me understood this 🥲 Thankyou so much mam for this explanation....you have saved me from failing in exam... thankyou so much again 🥲🥺
Sorry, we didn't see this post earlier. Yes, you can use the video for teaching. We can add Spanish subtitles if you can do the translation. Email mitxbiology@gmail.com if you are still interested.
Initially, the dna was negatively supercoiled with a LEFT handed turn. So by convention, W=-1. Topoisomerase 2 cut both strands and passed the dna through the gap thus created. Now the dna became positively supercoiled with one RIGHT handed turn. So W=+1. So from -1 to +1, the value of W increased by 2.
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Ok from what I understand, positive supercoiling is when u tighten the coils together such that there is more tension, so the double helix wraps around itself to relive this tension. helps. Negative supercoil is when u loosen the coil, but now that's it's loose it can wrap around another time, sort of like giving it extra space, I imagine this to be sort of like how earphones get coiled up in pockets, since they are in an unwound state, they are loose and can be pushed around easier causing coils. This can be thought of as a compensation mechanism, where the coil " tries " to become tighter. Hope this helps , although u probably already found ur answer by now lol
Hi what is RNA ? How many types of RNA? The structure of RNA what is Amino Acids ? The structure of Amino acids ? What is Genes ? what is Chromosome? can you share information of list of systems of the Human body ?
understood the whole concept of DNA topology in 7 minutes of this video than 7 hours of lecture. SO HELPFUL! THANK YOUU
Supercoiling is something I struggle to get my head around, so this was super helpful, thank you!
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Juji
Chutchattam
Hello sir
Boorchatta
7:27 *video suddenly became horror
thank you so much!!! your explanation was clear and easy to understand. My professors terrible and vague explanations was making me anxious and stressed - again thanks!!!
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why is it so hard for me to understand such logical problem ?
the way u guys explained using tubes was really helpful for visualization thank you very much for the video
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Is it available now @@MITxBio
You have no idea how much I'm thankful you.
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this is the best explained video I have watched so far about DNA supercoiling . Thank you so much.
Thank you, when I understood the importance of each topoisomerase, I understood the whole process.
nobody in the world could explain dna supercoiling this better..thanks.
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could you please explain the writhe thing again? What circular strand in the right direction, which colour are you on about?
Try this
ua-cam.com/video/aD67gi6bXws/v-deo.html
I'm just hugely grateful to you for making it so clear,I just banged my brain over this uncleared concept.
Makes the topic so clear to understand! Thanks
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Thank you for the video 😭 I finally understood!
One moment you're playing with threads the next you're learning topology of DNA with Knot theory. Every time now that I think of grandma knitting I think of knot theory.
Still a bit confused but definitely understand more than I did when I started!
Same
Extremely well done video. Thanks for the clear explanations.
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Awesome demo! This really cleared things up for me :)
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Thank you. This video helps me understand this section of genetics.
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thank-you for providing this easier version of DNA topology.
understood it by watchihg once, and my english is awefull. This video is excelent!
Not gonna lie that was 7 hours of lecture in that 7 mins
superb for explaining a most difficult concept
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A single thanks is not enough. Lots of love ❤❤❤❤
This video was so helpful, thank you!
Well explained, thanks
"Thanks for watching" haahaa. :P
Wow .....thanks for the demonstration ......... it cleared a lot of confusion .....🙂
Fantastic! More puzzle pieces!
Thank you very much. It was really helpful.
Exactly what I need thanks
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Awesome litterely, I understand the whole concept which was confusing me, thank you ❤
excelent video! thx for sharing!
thx for sharing! thx for sharing! thx for sharing! thx for sharing! thx for sharing! thx for sharing!
Superb... Plz make more videos... It would be helpful
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Really helpfull. Finaly I got it.Thank u for this one..
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thank you for this excellent video!
wonderful video, it helped me a lot.
Glad it helped!
Thanks for the video...nice explanation
Glad you liked it!
Is the course ready to start? it would be best if it does starts
Thanks for your interest. 7.28.1x Molecular Biology Part 1 starts next week. Registration open now for a Nov. 6 start. bit.ly/2AC9zP7
Great explaination
Thanks for your help ma'am
Thank you for this video ❤️
4:34 isn't the top and the bottom the same shit?
what difference does it make which strand goes on top?
This is a way for me thinking of the difference and if the coilong is negative or positive.
Put your thumb up like you would do when you wanna say "good job" for instance, do this with both of your hands.
Picture your thumbs being the "ends" of the figures in the video, or the curves furthest away from the crossing point- your right hand shows the right end/curve, and your left hand showing the left end/curve.
Then put your hands close to your desk and "rotate" your wrist forward so that your thumbs hit the desk.
Your right thumb (as the right end) will rotate in the same way (forward) as positive supercoils.
Your left hand (as the left end) will rotate in the same way (forward but the opposite end) as a negative supercoil.
Most people ar right handed, and so am I, so I associate right with positive and left with negative.
the direction of the helix changes RH to LH and their bookkeeping system labels those at +1 or -1. This is a net change of 2
I can't understand why in the overwound DNA the number of bp/turn decreases c.c
I mean, when we use the ethidium bromide, the number of bp/turn increases and the Wr tends to become positive.
Could someone explain me this?
Thanks
PS: The video is awesome
When you add intercalators like ethidium bromide, the binding of the intercalator to the base pairs results in a local unwinding of the helix by about 26 degrees - a reduction in twist (and an increase in writhe). Picture it - as the strands uncoil from each other slightly, the twists in the strand get further apart, so there are more bp/turn. However, this is UNtwisting the DNA from its relaxed state. In overwound DNA, intercalators are not used to wind it up. More twists are added to the double helix. As the twists in the strand increase in frequency, the number of bp/turn gets smaller.
so good!
Thank you 🔥
You're welcome 😊
Super helpful!
Question : why would any organism use Type 2 topoisomerase when using type one twice yields the same result ? one consumes ATP and the other Doesn't
When you have cell replication, in prokaryotes, you get two dna strand which are circular and connected with each-other thus when you want to separate the two cell dna circles from each-other you have to use the type two to losen up one of the helixes and take those two blunt ends to the other side, and from there each cell in the cell replication get a dna strand each. Otherwise you would have two interlocked dna circles. Do you understand why now?
Why can't i cross over the strand one at a time with type one instead of two at the same time with type two? It even said in the video at 4:39 that crossing over one by one yields the same result .
type two topoisomerase in bacteria helps in decreasing the linking number by two(refer Lehninger), but for eukaryotes type II topoisomerases
cannot underwind DNA (introduce negative supercoils),
but they can relax both positive and negative
supercoils, I think what is told in the video is a bit misleading
Wow!that was just awesome
Thank you for the feedback! Try our courses as well. bit.ly/2AC9zP7
After watching 20s to 30s of videos on thia topic... Finally!!!! I found someone who just explained this with so much ease and a dumb like me understood this 🥲
Thankyou so much mam for this explanation....you have saved me from failing in exam... thankyou so much again 🥲🥺
Also try our Introduction to Biology course! bit.ly/700xBio
i am still confused af :D
what happen if simply increase the length of both strand? will it result more turns and more supercoiling?
It was really helpful thanks:-)
Very informative.. Thank you
Glad it was helpful!
Thanks ma'am
May I use your video for teaching? I would need to add Spanish subtitles. Thanks!
Sorry, we didn't see this post earlier. Yes, you can use the video for teaching. We can add Spanish subtitles if you can do the translation. Email mitxbiology@gmail.com if you are still interested.
great video thank you:)
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Thanks!
very cool video
2:30 it's not underwound it wound more why you call it underwound?
helped a loooot..thnx
Thank you so much... now, finally i am able to understand DNA topology.... Best video...great...
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It was awesome mam..
How did the writhe number increased by 2 by type 2 topoisomerase???
Initially, the dna was negatively supercoiled with a LEFT handed turn. So by convention, W=-1. Topoisomerase 2 cut both strands and passed the dna through the gap thus created. Now the dna became positively supercoiled with one RIGHT handed turn. So W=+1.
So from -1 to +1, the value of W increased by 2.
thanks
I still don't get it but still great video!
Big FaN
Love from india
Please make subtitles in hindi
Please tell me what you used for the DNA model?
Lab tubing that we painted red and blue on the inside.
The course mentioned is not available currently, is the course going to happen again?
Yes, thanks for your interest! It will start in November and stay open for a longer period of time. Sign up on the wait list on our site to get a notification when registration opens. web.mit.edu/mitxbio/courses.html
The course registration is now open. Join us! bit.ly/2AC9zP7
Incredible
thank .... you....
♥️♥️♥️Very very thanks fr the vdo♥️♥️♥️♥️
i still didnt get the idea of positive and negative
Ok from what I understand, positive supercoiling is when u tighten the coils together such that there is more tension, so the double helix wraps around itself to relive this tension. helps.
Negative supercoil is when u loosen the coil, but now that's it's loose it can wrap around another time, sort of like giving it extra space, I imagine this to be sort of like how earphones get coiled up in pockets, since they are in an unwound state, they are loose and can be pushed around easier causing coils.
This can be thought of as a compensation mechanism, where the coil " tries " to become tighter.
Hope this helps , although u probably already found ur answer by now lol
Can you please add the French subtitles? it's hard to concentrate translating your words and trying to understand
شكراً
Great video!!! I was just wondering how does negatively supercoil DNA store energy in it's coil?
Upload about the Central Dogma!
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please upload translation
If you know someone who can do the translation (and tell us what language), we are happy to upload additional transcripts.
Wait guys what does this have to do with topology of the DNA
everything
6:24
While this is intriguing, evolutionists would find their job, hypothesizing a theory, further complicated! Great!
Add Filipino subtitles
goog video
Hi
what is RNA ?
How many types of RNA?
The structure of RNA
what is Amino Acids ?
The structure of Amino acids ?
What is Genes ?
what is Chromosome?
can you share information of list of systems of the Human body ?
I don't understand scientific english very well any translation to french
If you know someone who can do the translation, we are happy to post additional subtitles.
but why does't dna get tangled into a mess of knotsssssss
That's the requirement, that's how tgey are packaged and chromosomes are formed.
Because there are topoisomerase which relaxes the DNA
Wow
Cure HIV crispr cas 9.
❤❤❤
chome emmer noni drus aber jäno
fml
talking like robots is not helpful. thanks
The accent is so irritating.. Not clearly understand.. 👎👎👎
ua-cam.com/video/aD67gi6bXws/v-deo.html
Try this to solve your problem.
Give comment about the video